1. Field of the Invention
The present invention relates in general to markers used in radiology, and in particular to an anatomical marker used to orient to a patient's anatomical position in x-ray and fluoroscopy procedures.
2. Description of the Related Art
Markers are often used to identify a body part shown in an x-ray image. X-rays which are absorbed by markers do not appear on x-ray sensitive media. In fluoroscopy, real-time x-ray images are displayed on a video monitor. Fluoroscopy is often combined with other medical procedures.
Paramount to fluoroscopy is initially orienting the x-ray image to the patient's body position. One problem is that images must be oriented in left-right, cranio-caudal, and antero-posterior position before a procedure can begin. Although bony landmarks are often used to orient the patient's body position with the image, fluoroscopy images typically do not include the entirety of a patient's body. As a result, it is difficult to ascertain the body position of a patient in a given fluoroscopy image. Also, given the axial symmetry of bony landmarks in x-ray, it is difficult to quickly, clearly, and confidently delineate left, right, and cranio-caudal positions. Practitioners must adjust the image repeatedly until the patient's body position and the x-ray image are properly correlated. The image can be rotated and reversed, typically on a circular display.
In some radiological procedures, a patient faces an x-ray emitter. The patient is then in antero-posterior position: the front side of the patient is closer to the viewer, and the patient's back is further from the viewer. In some other radiological procedures, the patient faces away from the x-ray emitter, in postero-anterior position.
Single piece “L” or “R” markers are known in the related art to identify the left or right side, respectively. Two or more separate markers are also known in the related art. The related art teaches various marker systems, some of which include: U.S. Pat. Nos. 1,576,781, 4,274,006, 4,506,676, 5,052,035, 5,193,106, 5,394,456, 5,469,847, 6,160,870, 6,354,737, 6,470,207, 7,092,492, 7,123,690, and 7,313,430; USPA 20040081284, 20050157847, and 20060065273; and international applications WO96/025111, WO05/018288, and WO06/036248. An online catalog of Techno-Aide, Inc. of Nashville, Tenn. teaches markers known in the related art.
However, markers in the related art consistently do not provide simultaneous orientation as to antero-posterior, cranio-caudal and left-right positioning by a single marker. Also, placing an “R” marker on the patient's left side results in incorrect image orientation; the “R” appears on the right side of the image, which initially appears correct. However, in an antero-posterior view of the patient, the patient's left side is on the right side of the image; thus, the “R” should appear on the left side of the image in correlation with the patient's right side. Misorientation can lead to accidents in medical procedures if an incorrect position is not identified, especially prior to invasive procedures. Confusion results when an image appears reversed on a left-right axis, or unclear as to cranio-caudal or antero-posterior orientation. If the incorrect position is only identified after a procedure begins, the misoriented image has to be corrected during the procedure, increasing procedure time.
Multiple individual markers could be used to provide simultaneous orientation as to multiple directions, but their relative orientation is not fixed and is subject to error. Also, using multiple markers requires extra time, slowing down positioning. Separate pieces can also be easily lost. Even with accurately placed separate left and right markers, the patient's cranio-caudal position in the image is not necessarily clear. Although cranio-caudal orientation can be inferred by using the spine as a bony landmark, this does not immediately confer left-right orientation with respect to the patient's body. Further, the spine is not always in view.
It can be seen, then, that there is a need in the art for a marker that provides immediate visual correlation as to multiple directional aspects of a patient's anatomy, so that a fluoroscopy can proceed more quickly, with greater accuracy, and greater confidence. It can also be seen that there is a need to provide an easy-to-use, single piece marker that quickly provides orientation as to the anterior, posterior, left, right, cranial, and caudal directions without excessive time to position, and without multiple pieces. Also, it can be seen that there is a need to enhance quality of healthcare service so that x-ray images and records are clearer and more effective, especially in life-threatening medical situations or in the context of litigation. Moreover, it can be seen that there is a need to reduce unnecessary radiation exposure. Finally, it can be seen that there is a need to address any combination of these problems.